Abstract

Two-dimensional (2D) materials have emerged as a novel toolbox to build new materials and devices atom-by-atom. By stacking and twisting 2D materials, new ways to control light and electrons at the atomic scale. In particular, we will show nano-optoelectronic devices for applications as well as the novel nanophotonic properties¹. The limits of quantum light-matter interactions have been challenged by approaching optical field confinement down to the length-scale of single atoms².

We will also present nano-optoelectronic studies on twisted bilayer graphene using scanning near-field optical microscopy³,[4]. Twisted bilayer graphene near the magic angle (MABG) exhibit strongly correlated phases have been observed, including superconductivity and the Mott-like insulating state⁵. Several device applications, such as detectors for infrared and THz light will also be discussed⁶.

References

1. Polaritons in layered two-dimensional materials. Low et al., Nature Materials (2017).

2. Far-field excitation of single graphene plasmon cavities with ultracompressed mode volumes. Epstein et al., Science (2020).

3. Collective excitations in twisted bilayer graphene close to the magic angle. Hesp et al., Arxiv 1910.07893 (2019).

4. Nano-imaging photoresponse in a moiré unit cell of minimally twisted bilayer graphene. Hesp et al., Nature Communications (2020).

5. Unconventional superconductivity in magic-angle graphene superlattices. Y. Cao et al. Nature (2018).

6. Plasmonic antenna coupling to hyperbolic phonon-polaritons for sensitive and fast mid-infrared photodetection with graphene. Castilla et al., Nano Letters (2019)